1. Field of the Invention
The present invention relates to a damper apparatus provided in an ink jet printer having a print head configured to eject ink and a tank in which ink to be supplied to the print head is stored and is configured to supply the ink supplied from the tank to the print head while suppressing a pressure fluctuation.
2. Description of the Background Art
Examples of known ink jet printers of the related art include an ink jet printer including an ink jet head as a print head configured to eject ink, a main tank as a tank in which ink to be supplied to the ink jet head is stored, and a sub tank as a damper apparatus configured to supply the ink supplied from the main tank to the ink jet head while suppressing a pressure fluctuation (see JP-A-2011-156859).
The sub tank of this ink jet printer is formed with an ink storage chamber configured to store ink therein. The sub tank also includes a connector portion as an ink introducing portion for introducing ink supplied from the outside into the ink storage chamber and a connector portion as an ink discharging portion for discharging ink in the ink storage chamber to the outside.
The main tank of this ink jet printer is configured to store ink to be introduced into the ink storage chamber of the sub tank via the ink introducing portion of the sub tank.
The ink jet head of this ink jet printer is configured to be supplied with ink discharged from the ink storage chamber of the sub tank via the ink discharging portion of the sub tank.
This ink jet printer includes a first ink flow channel as a normal flow channel, which is a flow channel ranging from the main tank to the ink introducing portion of the sub tank, a third ink flow channel as a circulating flow channel, which is a flow channel ranging from the ink discharging portion of the sub tank to the first ink flow channel, a fluid feeding pump for normal operation as ink supplying device configured to supply ink from the main tank to the ink introducing portion of the sub tank via the first ink flow channel, and a fluid feeding pump for circulation as an ink supplying device configured to supply ink from the ink discharging portion of the sub tank to the ink introducing portion of the sub tank via the third ink flow channel and the first ink flow channel.
This ink jet printer is capable of suppressing precipitating of fine particles of ink such as white ink in the ink storage chamber of the sub tank, the third ink flow channel and the first ink flow channel by circulating the ink among the ink storage chamber of the sub tank, the third ink flow channel, and the first ink flow channel by activating a fluid feeding pump for circulation. Therefore, this ink jet printer is capable of suppressing failures such as printing with ink having low concentration of the fine particles due to precipitating of the fine particles or printing with ink with high concentration of the fine particle due to flashing of precipitated fine particles at a burst.
However, in the ink jet printer of the related art, since a surface area of the ink storage chamber of the sub tank on which ink flows is larger than surface areas of the first ink flow channel and the third ink flow channel on which the ink flows, there is a problem that a flow velocity of ink required for suppressing precipitating of the fine particles of the ink in the ink storage chamber of the sub tank is faster than a flow velocity of the ink required for suppressing precipitating of the fine particles of the ink in the first ink flow channel and the third ink flow channel. Therefore, in the ink jet printer of the related art, when suppressing precipitating of the fine particles of the ink in the ink storage chamber of the sub tank, the flow velocity of ink needs to be faster than that in a case of suppressing only the precipitating of the fine particles of the ink in the first ink flow channel and the third ink flow channel. Therefore, for example, an increase of noise generated by the flow of ink, lowering of durability of the fluid feeding pump for circulation due to an increase of load of the fluid feeding pump for circulation which creates a flow of ink, or an increase of consumed energy by the fluid feeding pump for circulation due to the increase of the load of the fluid feeding pump for circulation may result.